1. Field of the Invention
One embodiment of the present invention relates to a method for manufacturing an electrode and a method for manufacturing a power storage device and a power generation and a storage device having the electrode.
2. Description of the Related Art
In recent years, with an increase of environmental engineering, development of power generation devices which pose fewer burdens on the environment (e.g., solar power generation device) than power generation devices using conventional power generation methods has been actively conducted. Concurrently with the development of power generation device, development of power storage device has also been underway.
As an example of a power storage device, a lithium ion battery can be given. A lithium ion battery is widely prevalent since energy density thereof is high and the lithium ion battery is well suited for miniaturization. As a negative electrode material of a lithium ion battery, a material in/from which lithium ions can be inserted and extracted is preferably used. Although graphite or silicon can be given as examples of the negative electrode material of a lithium ion battery, silicon is especially preferable. This is because theoretical capacity of silicon is ten times as high as that of graphite and silicon is expected to be a host material of lithium ions (e.g., see Patent Document 1). In addition, as another example of a power storage device, development of an asymmetric capacitor and a hybrid capacitor has also been underway.
However, in the case where silicon or the like is used for an electrode of a lithium ion battery, volume expansion in the electrode becomes a problem in some cases. The volume expansion in the electrode causes deterioration in characteristics of the electrode and leads to reduction in yield and reliability. A lithium ion battery disclosed in Patent Document 2 includes a stack having expansion cavities for an electrode and each expansion cavity is formed in a recessed zone.